Inkjet, deskjet and laserjet printers have a paper tray to store a paper stack for printing. From this tray, stored paper is positioned for picking (removal from the paper stack) and then transported for printing.
The paper in a paper tray is generally moved into a position from which the paper can be picked, in order to aid picking of the paper by the printer, when the tray has been inserted into a printer. Technically, the mechanisms for placing paper in a position from which the paper can be picked may be contained within both the tray and the printer, whereby the mechanisms interact with one another. Having two separate mechanisms, which come together in order to function properly, makes it desirable to have high dimensional accuracy and low levels of stack tolerances (the mismatch between the height of the top of the stack of paper in the tray and the paper receiving part of the printer). Additionally, high cost may be incurred both from the high number of parts and from the assembly of these complicated mechanisms.
For a user loading paper, depending on the tray being used, a specific set of do's, don'ts and check procedures are performed to ensure the product functions correctly. Failure to do so may result in paper not being picked. Such a set of check procedures may not be regarded as user-friendly or robust. Within repair centers, failure of mechanisms to elevate paper for pick results in repairs (or even replacement) of the printer or the tray or both, which is a very costly solution. In addition, trouble-shooting for the root cause of such a picking problem can be time consuming and tedious.